Modern electronic computers, as we know them today, have many of their roots in the distant past. The Virtual Computer History Museum at Virginia Tech presents a Timeline of Events in Computer History at their website which offers an overview of the development of the computer which you may be interested in consulting for more detail on their early incarnations.
The abacus can be considered a calculator of sorts, and slide rules and other mechanical calculators were created in the 1600s.
In 1822, Charles Babbage, British mathematician, completed the construction of a mechanical device capable of calculating tables of logarithmic and trigonometric functions to six decimal places. He then began work on a steam powered calculating machine he called the Difference Engine, the purpose of which was to mechanically create mathematical tables for use by the government, the military, the banking business, and advanced engineering.
Difference Engine built in 1991 from Babbage’s drawings photo from the Timeline of Events in Computer History website. He received government backing for the project, but it was never completed, partially because he continually tinkered with the design. A working model was produced in 1991 to commemorate the bicentenary Babbage’s birth by the Science Museum in Kensington, England, based on his construction drawings.
In 1834 he started to design the Analytical Engine. This is the true precursor of today’s computers. This mechanical device used punched cards, one set for operations and another for variables.The Analytical Engine was a major leap forward in concept from the Difference Engine. It was not just a calculator of tables, but a mechanical processor. It was to be able to store variables and print results. It was designed not be limited to the simple performance sequential calculations to produce a static table, but instead to choose to perform the next operation depending on the results of the previous one. The idea was to make it useful in many more applications than the Difference Engine. While parts of the machine were built it was never completed as a whole.
Herman Hollerith received a contract to deliver data processing equipment to aid in the tabulation of the data from the 1890 US Census.
It had taken the Census Bureau seven years to tabulate the 1880 census, making the the data generated obsolete before it could be completely tabulated. Hollerith??s machine, using punchcards to enter the data, completed tabulating the much more detailed and extensive data from the 1890 census in just six weeks time. The company he founded, the Tabulating Machine Company, eventually became part of the Calculating-Tabulating-Recording (C-T-R) company in 1911. In 1924, the company changed its name to International Business Machines, now commonly known as IBM.
In the early 1930s, Vannevar Bush, of MIT, built a large-scale mechanical differential analyzer. This differential analyzer was the first truly successful general equation solver. It was still not electronic but it could handle sixth-order differential equations. The output was in the form of automatically plotted charts.
A more advanced model, financed by the Rockefeller Foundation used electronic components and was in service in time for use during the Second World War. This machine weighed on the order of 100 tons, employed in excess of 2000 vacuum tubes, 200 miles of wire, 150 motors, and thousands of relays. Data input was via punched paper tapes. Bush predicted many of the uses and advances in computer technology in his 1945 article for the Atlantic Monthly, As We May Think . It makes interesting and illuminating reading even today.
The need for raw computation during World War II created a condition in which the creation of calculation devices for producing firing tables for artillery and navigation tables for naval ships, like those which Babbage’s Difference Engine had been intended to produce, took precidence over complete, real time computational devices.
Some progress was made however. The British constructed a series of machines to facilitate in the decryption of coded German military messages at their code-breaking facility at Bletchley Park.
William Shockley, John Bardeen, and Walter Brattain invented the transistor in 1947. These small devices revolutionized the computer, allowing a level of miniaturization and reliability that would have been impossible using vacuum tube technology.
Eckert and Mauchly established the Electronic Control Corporation in late 1946 with a plan to build the Universal Automatic Computer (UNIVAC). They built the BINAC for Northrup Aviation, and were taken over by Remington-Rand before the UNIVAC was completed.
The Whirlwind – photo from
the Timeline of Events in
Computer History website
Jay Forrester, Bob Everett built the first real-time processing computer, the Whirlwind. The Whirlwind Project furthered progress in the development of core memory by using the technique of stringing the cores onto a matrix of wires and thus producing a random access memory.
In 1953 IBM entered the electronic computer business with its Type 701 EDPM. The 700 series of machines, including the 704, 709, and eventually the 7090 and 7094, went on to dominate the mainframe market for the next decade, and made IBM the premier manufacturer of computers in the world during that period.
The year 1957 saw the advent of magnetic disk storage, making use of read/write heads to provide a semi-random access capability and a storage capacity akin to that of magnetic tape. The IBM 305 RAMAC was the first disk memory system. John Backus, after three years of development, delivered the first FORTRAN compiler for the IBM 704 opening the way to much easier programming techniques for electronic computers.
In 1958, Jack St. Clair Kilby integrated a transistor with resistors and capacitors on a single semiconductor chip, and the era of true miniaturization of components had begun.
By 1960 the Conference on Data System Languages, led by Joe Wegstein, developed a new language in a very short period of time, creating the first standardized business computer programming language, COBOL (Common Business Oriented Language). It would become the most extensively used programming language for the next 20 years.
In 1963 a standard was formulated for the first time which allowed computers to interchange information, with the creation of ASCII codes for common characters. This system would take almost 15 years before it would become accepted as commonplace.
By the mid-60’s IBM computers were being used for the real-time processing of airline reservations. Large computers were still the rule, though they were becoming more standardized, with interchangeable components, and sophisticated. IBM brought out its System/360. This system used interchangeable software, components, and peripheral equipment. Instead of buying a whole new system when the need came, the customer could simply upgrade parts of their hardware.